Colour-changing windows get a palette upgrade

A new research paper could show how to easily and inexpensively expand the colour palette for glass that changes colour based on voltage. Researchers working on nanophotonics at Rice University have released a new report detailing how the use of the hydrocarbon molecule perylene can create glass able to turn two different colours at low voltage.

“When we put charges on the molecules or remove charges from them, they go from clear to a vivid color,” said Halas, director of the Laboratory for Nanophotonics (LANP), lead scientist on the new study and the director of Rice’s Smalley-Curl Institute.

“We sandwiched these molecules between glass, and we’re able to make something that looks like a window, but the window changes to different types of colour depending on how we apply a very low voltage.”

The new colour-changing glass varies its colouration depending on polarity, meaning that a positive voltage will produce one colour and a negative voltage another. The importance of the Rice team’s new method is that until now, multicolour varieties of such glass have required a much more significant voltage, limiting their use.

The type of glass itself, changing colour as a result of applied voltage, is known as electrochromic  glass and is enjoying growing popularity. The market for such material has been estimated at a value of more than $2.5bn by 2020. Aside from the visual appeal, electrochromic glass is in demand for its light and heat-blocking properties.

Grant Stec and Adam Lauchner of Rice University’s Laboratory for Nanophotonics show off the glass. Images courtesy of Jeff Fitlow/Rice University

In 2013, then-Rice physicist Alejandro Manjavacas found that polycyclic aromatic hydrocarbons (PAHs), the family of molecules that perylene belongs to, with just a few carbon rings should produce visible plasmons. There are dozens of PAHs, all of which contain rings of carbon atoms that are decorated with hydrogen atoms.

Waves of energy that can interact with and harvest energy from passing light depending on their frequency, plasmons are a rhythmic movement in the sea of electrons that constantly flow across the surface of conductive nanoparticles. Building off Manjavacas’ work, the researchers were able to work out that the PAH plasmons were highly sensitive to charge, leading them to the conclusion they could be easily utilised for electrochromic glass.

“Dr Halas learned that one of the major hurdles in the electrochromic device industry was making a window that could be clear in one state and completely black in another,” study co-lead author Grant Stec said. “We set out to do that and found a combination of PAHs that captured no visible light at zero volts and almost all visible light at low voltage.”

The new project took almost two years to complete and relied on Stec’s design of the perylene-containing nonwater-based conductive gel that’s sandwiched between glass layers. In experimenting with the assembled window, the team found that just 4 volts was enough to turn the clear window greenish-yellow, and applying negative 3.5 volts turned it blue.

Later in the project, the team produced a second window capable of going from clear to black. In all their experiments, they found that the colour change takes a few minutes but Halas said that the transition time is improvable with additional engineering.

DJI’s First Drone Arena in Tokyo to Open This Saturday

Consumer drone giant DJI will open its first Japanese drone arena in the city of Tokyo this Saturday, providing a space for both hardened professionals and curious newcomers to hone their flying skills.

The arena, which covers an area of 535 square metres, will not only include a large flying area complete with obstacles, but also offer a store where visitors can purchase the latest DJI drones and a technical support area where drone owners can get help with quadcopter issues.

The hope is that the arena will allow those who are curious about the technology but currently lack the space to try it out to get involved.

“As interest around our aerial technology continues to grow, the DJI Arena concept is a new way for us to engage not just hobbyists but also those considering this technology for their work or just for the thrill of flying,” said Moon Tae-Hyun, DJI’s director of brand management and operations.

“Having the opportunity to get behind the remote controller and trying out the technology first hand can enrich the customer experience. When people understand how it works or how easy it is to fly, they will discover what this technology can do for them and see a whole new world of possibilities.”

Images courtesy of DJI

In addition to its general sessions, which will allow members of the public to drop by and try their hand at flying drones, the arena will also offer private hire, including corporate events. For some companies, then, drone flying could become the new golf.

There will also be regular events, allowing pros to compete against one another, and drone training, in the form of DJI’s New Pilot Experience Program, for newcomers.

The arena has been launched in partnership with Japan Circuit, a developer of connected technologies, including drones.

“We are extremely excited to partner with DJI to launch the first DJI Arena in Japan,” said Tetsuhiro Sakai, CEO of Japan Circuit.

“Whether you are a skilled drone pilot or someone looking for their first drone, we welcome everyone to come and learn, experience it for themselves, and have fun. The new DJI Arena will not only serve as a gathering place for drone enthusiasts but also help us reach new customers and anyone interested in learning about this incredible technology.”

The arena is the second of its kind to be launched by DJI, with the first located in Yongin, South Korea, and detailed in the video above. .

Having opened in 2016, the area has attracted visitors from around the world, demonstrating serious demand for this type of entertainment space.

If the Tokyo launch goes well, it’s likely DJI will look at rolling out its arena concept to other cities, perhaps even bringing the model to the US and Europe.

For now, however, those who are interested can book time at the Tokyo arena here.

Commercial Human Spaceflight Advances Prompt Calls for Space Safety Institute

Commercial human spaceflight has been a long-held dream, but now it is finally poised to become a reality. Companies including Virgin Galactic and SpaceX are inching ever closer to taking private citizens into space, and there are serious plans for spaceports in several parts of the world, including Hawaii, the US, and Scotland, the UK.

But while the industry is advancing, the legal side of this fledgling commercial space industry remains underdeveloped, leading to calls for the development of an organisation to establish a framework for the safe operation of spaceports for human commercial spaceflights.

Writing in the journal New Space, Mclee Kerolle, from the United States International Institute of Space Law in Paris, France, has proposed the establishment of a Space Safety Institute recognised by the US congress and the United Nations.

This institute would “develop, enforce and adopt standards of excellence”, allowing the industry to develop while protecting it from liability and insurance risks.

“Currently, no international regulatory body exists to regulate the operation of spaceports,” he wrote. “This is unfortunate because while the advent of commercial human spaceflight industry is imminent, a majority of the focus from the legal community will be on regulating spaceflights and space access vehicles.

“However, the regulation of spaceports should be viewed in the same light as the rest of the commercial human spaceflight industry.”

The article focuses particularly on the establishment of a spaceport at the Kona International Airport in Keahole, Hawaii. At present, the spaceport’s development is subject to regulation by the Federal Aviation Authority, however there are aspects to spaceport development that do not apply to conventional aviation operations.

A spacesuit design for commercial flights developed by SpaceX. Featured image: SpaceX’s proposed spaceport for its conceptual interplanetary transport system. All images courtesy of SpaceX

The institute would be designed to first and foremost ensure safety within the industry, so it would be important, according to Kerolle, to ensure it was made up of individuals with expertise in the field, rather than bureaucrats.

“To make sure that this flexibility is inherent in a Space Safety Institute, the organization should be composed of individuals within the industry as opposed to government officials who are not familiar with the commercial human spaceflight industry,” he wrote.

“As a result, this should protect the commercial human spaceflight industry to some liability exposure, as well as promote growth in the industry to ensure the industry’s survival.”